Merge pull request #4029 from element-hq/feature/bma/eventCache

Add a feature flag to be able to enable the event cache

libraries/featureflag/api/src/main/kotlin/io/element/android/libraries/featureflag/api/FeatureFlags.kt

@@ -161,4 +161,11 @@ enum class FeatureFlags(
         defaultValue = { buildMeta -> buildMeta.buildType != BuildType.RELEASE },
         isFinished = false,
     ),
+    EventCache(
+        key = "feature.event_cache",
+        title = "Use SDK Event cache",
+        description = "Warning: you must kill and restart the app for the change to take effect.",
+        defaultValue = { false },
+        isFinished = false,
+    ),
 }

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/MatrixRoom.kt

@@ -232,6 +232,11 @@ interface MatrixRoom : Closeable {
      */
     suspend fun setUnreadFlag(isUnread: Boolean): Result<Unit>
 
+    /**
+     * Clear the event cache storage for the current room.
+     */
+    suspend fun clearEventCacheStorage(): Result<Unit>
+
     /**
      * Share a location message in the room.
      *

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/RustMatrixClientFactory.kt

@@ -109,9 +109,7 @@ class RustMatrixClientFactory @Inject constructor(
             .addRootCertificates(userCertificatesProvider.provides())
             .autoEnableBackups(true)
             .autoEnableCrossSigning(true)
-            // TODO Add a feature flag to enable persistent storage
-            // See https://github.com/matrix-org/matrix-rust-sdk/pull/4396
-            .useEventCachePersistentStorage(false)
+            .useEventCachePersistentStorage(featureFlagService.isFeatureEnabled(FeatureFlags.EventCache))
             .roomKeyRecipientStrategy(
                 strategy = if (featureFlagService.isFeatureEnabled(FeatureFlags.OnlySignedDeviceIsolationMode)) {
                     CollectStrategy.IdentityBasedStrategy

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/RustMatrixRoom.kt

@@ -569,6 +569,12 @@ class RustMatrixRoom(
         }
     }
 
+    override suspend fun clearEventCacheStorage(): Result<Unit> = withContext(roomDispatcher) {
+        runCatching {
+            innerRoom.clearEventCacheStorage()
+        }
+    }
+
     override suspend fun kickUser(userId: UserId, reason: String?): Result<Unit> = withContext(roomDispatcher) {
         runCatching {
             innerRoom.kickUser(userId.value, reason)

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/room/FakeMatrixRoom.kt

@@ -574,6 +574,10 @@ class FakeMatrixRoom(
     fun givenRoomMembersState(state: MatrixRoomMembersState) {
         membersStateFlow.value = state
     }
+
+    override suspend fun clearEventCacheStorage(): Result<Unit> {
+        return Result.success(Unit)
+    }
 }
 
 fun defaultRoomPowerLevels() = MatrixRoomPowerLevels(